Two-stage throttle-valve for percussive tools.



c. H. HAESELER.

TWO STAGE THROTTLE VALVE FOR PERCUSSIVE TOOLS.

APPLICATION FILED JULY 17. 1916.

Patented Feb. 6

1111 .lll llll'lnll llll lll Ill-l llll II-ll ATTORNEYS CHARLES H. HAESELER, OF CHICAGO, ILLINOIS.

TWO-STAGE THROTTLE-VALVE FOR I'ERCUSSIVE TOOLS.

Specification of Letters Fatent. it Patgntefl Feb, 6, 1911?,-

Application filed July 17, 1916. Serial No. 109,655.

To all whom it may concern:

Be it known that I, CHARLES H. Hnnsnrnn, a citizen of the United States, residing at Chicago, in the county of Cook, State of and arrangement of a throttle valve bushing valve, preferably located in the grasping portion of the handle and adapted to control the passage of live motive fluid to effect the operation of the percussive tool.

It further consists of a novel construction of a throttle valve wherein the initial movement of the controlling lever provides for" the introduction into the tool of a minimum amount of motive fluid, and on a further movement of the control-1mg needle, provides for the introduction of a larger 1 amount of motive fluid.

It further consists of a novel construction and a handle which is adapted to receive such bushing.

.It further consists of a novel construction and arrangement of a main throttle valve.

It further consists of a novel construction and rrangement of' an auxiliary throttle valve, and novel means for guiding it.

It further consists of novel means for preventing the leakage of fluid around the auxiliary valve to the atmosphere.

It further consists of a novel means cooperating with the main and auxiliary valves to effect their movement.

Other novel features of construction and advantage will hereinafter appear more clearly in the detailed description thereof.

For the purpose of illustrating my invention, I have shown in the accompanying drawings, a typical embodiment which well illustrates the principle of the invention, and which in practice will give satisfactory and reliable results, but it is of course to be understood that this embodiment is typical only and that the various instrumentalities of which my invention consists can be variously arranged and organized and my' lnvention is not limited to the exact arrangement and organization of these instrumentalities as herein set forth.

Figure 1 represents, in elevation, a longitudinal section of a two stage throttle mechanism for percussive tools embodying my invlention, in conjunction with a percussive too Fig. 2 represents a sectional elevation of the two stage throttle mechanism, showing the parts inth positions they assume when the controlling lever is initially depressed.

ig. 3 represents a sectional. elevation similar toFig. 2, but showing the parts in the position which they assume when the controlling lever is further deprtssed.

Fig. 4 represents a sectional view of the throttle valve bushing, in detached position.

Fig. 5 represents a side elevation of the auxiliary valve, in detached position.

Fig. 6 represents a sectional elevation of vthe main throttle-valve, in detached position.

Similar numerals of reference indicate .corresponding parts in the figures.

Referring to the drawings l designates a percussive tool of any desired or conventional type, but which for purpose of illustration, I have shown as conforming substantially as to its cycle of operation to that described andbroadly claimed .in my co-pending application for Letters Patent, Serial No. 97 ,014, filed by me onthe 12th day of May, 1916. The percussive tool, as illustrated, comprises a casing 2 in which is adapted to reciprocate a hammering piston 3, the blows of which are imparted to a working tool 4. 5 designates a head-block in which, in the type illustrated, .islocated a main distribution valve 6, which may be of any desired or conventional type and which may be located in the head block 5 or in the casing 2, as is obvious.

7 designates the grasping handle, which as is obvious, may be of the pistol grip type or of the closed type, but for purposes of illustration, I have preferred to show this grasping portion as conforming to the pistol grip type of handle. 8 designates the motive fluid inlet, which is provided in the usual manner with a nipple 9 adapted to be connected with the flexible hose which leads to the source of motive fluid supply. The grasping portion 7 has an aperture 10 and in such portion is formed a groove 15,

the bottom of which is provided with a series of ports 16, said groove being located intermediate the ends of the throttle valve bushing. At one end, the throttle valve bushing is of reduced diameter, as at 17, in order to engage the walls of the aperture 12, and such portion 17 is slotted, as indicated at 18. The bushing 11 is provided with a portion 19 f greater diameter, which communicates with a bore 20 of lesser diameter, and between such diameters is formed a valve seat 21.

22 designates a main throttle valve which is provided at one end with a head 23 adapted to fit the bore 19 of the throttle valve. This head is provided with an inclined wall 24 forming a seat which ooiiperates with the valve seat 21 in the throttle valve opening. The outer periphery of the valve 22 is provided with an annular groove 25 and its inner end with a head 26 which is adapted to slide within the bore 20 ofthe'throttle valve opening.

The main throttle valve 22 is provided with a differential bore 27, the portion 28 of which forms a bearing for the stem 29 of the auxiliary valve 30, which latter is provided with an inclined or beveled face in closed position. The auxiliary valve 30.

is provided with a forwardly extending stem 37 which is guided in an aperture 38 in a.

closure 39, which latter is in threaded engagement with the end of the throttle valve bushing 11.

40 designates a spring interposed between the valve head 30 and the closure 39, whereby the valve 30 is normally maintained in its closed position.

41 designates a ball located inthe chamber 36 and 'against this ball bears the arm 42 of a lever 43, which is pivoted at 44 in the slot 13. The lever 43 is provided in any desired manner with a head 45 against which the operator presses his thumb in the usual manner. The main inlet 8 communicates by means of a port 46 in the valve. bushing with the chamber 47. When the throttle bushing is inserted into position, the groove 15 forms with the wall of the bore 10 a chamber 48 which communicates by means of a passage 49 with the main distribution valve 6.

It will be seen that the throttle lever 43 is guided in the slot 18 of the throttle valve bushing 11.

The operation of my present invention will now be readily apparent to those skilled in this art, and is as follows:

When the parts are in the position seen in Fig. 1, both the main and the auxiliary valves are in their closed position. Assuming now that the operator presses down the controlling lever 43 from the position seen in Fig. 1 into that seen in Fig. 2, it will be seen that the arm 42 pressing against the "ball or anti-friction device 41 causes the auxiliary valve 30 to move forward against the tension of the spring 40, thereby permitting live motive fluid, which has been admitted to the chamber 46 through the motive fluid inlet 8 and the port 46, to pass into the chamber 33, thence through ports 34 into the chamber 35 formed between the main Valve and the throttle valve bushing 11. The motive'fluid'may then pass through the port 16 into the annular groove or chamber 48, thence into the passage 49, to effect the actuation of the percussive tool. In the form illustrated, to show one manner of carrying out my invention in practice, the motive fluid passes from the passage 49 to a fluid distribution valve 6, which distributes the live motive fluid to opposite ends of the piston chamber to effect the reciprocation ,of the hammering piston 3.

When the operator moves the controlling lever 43-from the position seen in Fig. 2 into that seen in Fig. 3, the ball 41, which also serves as. a valve to prevent leakage of mo tive fluid around the stem 29 of the auxiliary valve 30, the main valve which has been maintained seated in its closed position due to the pressure of live motive fluid is advanced into the position seen in Fig. 3. The live motive fluid can now freely pass to the chamber 35, since both the main and auxiliary valves are in open vposition. The live motive fluid then passes through the port 16, chamber 48 and passage 49 in a manner similar to that already described in connection with the first stage of the operation. As soon as the operator releases his pressure on the controlling lever 43, the spring 40 which has been compressed causes the auxiliary valve to move rearwardly to its seat and then both the main and auxiliary valves move rearwardly in unison until the main valve is seated. The ball 41 and the controleia-lee ling or throttle lever 43 are also returned to and retained in their normal position, as

seen in Fig. 1.

It will be seen that the ball il-cooperates with both of the valves to efiiect their forward movement and it also serves to closethe end of the aperture through which the a spring or tension device which cooperates with the auxiliary valve and through it with the. main valve to maintain the valves in their closed position. When it is desired to start the tool, the auxiliary valve may be easily opened, due to its small area and after the tool is started, the fullpressure of the live motive fluid may be permitted to pass through the handle to the piston or its equivalent. The auxiliary valve is guided in the main valve and in the closure for the bushing, and the main valve is guided in the valve bushing so that the parts are always retained in proper alinement. It will be understood by those skilled in the art, that when a pneumatic hammer is used for chipping metal, it is desirable to start the cutting tool at the minimum speed and power of the hammering piston, and then after the chip or cut is well started to increase the speed and power of the hammer, or in other words, the reciprocations of the hammering piston to the maximum and to so continue-until nearly the end of the cut, when it is again desirable to reduce the speed and power to the minimum, which can be efiected by releasing the-pressure upon the manually operated lever.

It will be further apparent to those skilled in the art, that it is also desirable when starting to head up a rivet to operate the hammer at the minimum speed which is effected by the initial depression of the manuallypperated lever until the end of the rivet is sufiiciently formed to holdthe working tool or rivet set in position and to then fully drive the rivet by the application of the maximum speed and power,

which is eifected by the further depression of said manually operated lever, which unseats the main valve. By the use of my novel two stage throttle described provided with the main and auxiliary valves, the minimum and maximum speed and power of the hammering piston are arranged in separate and well defined steps and are both under the immediate control of the operator.

It will thus be seen from the foregoing that my invention is of great importance in connection with the two classes of work for which pneumatic tools of this general character are employed, to wit, for chipping metal and for riveting, and Ihave found from practical experience that pneumatic tools equipped with my invention possess marked advantages in efficiency. and economy of operation. I The ball or its equivalent employed serves as a connecting means between the throttle or handle lever and the main and auxiliary valves, and also serves to seal the end of the passage through which the auxiliary valve stem extends when the auxiliary valve is open, so that there is no chance of any leakage of live motive fluid to the atmosphere.

I am the first in the art to employ in conjunction with a pneumatic tool handle, a two-stage throttle valve mechanism of any character, wherein the auxiliary valve is initially unseated by the initial movement of .valve, and my claims to these features are to be interpreted with the scope awarded to inventions of this character.

It will be understood from the foregoing that the main object of the two-stage throttle valve is to'provide a construction that will enable the minimum and maximum speeds of the hammering piston to have a well defined stage or period of rest between such speeds. "With the ordinary throttle valve construction, the jar of the hammer prevents the operator from maintaining an even minimum speed as the valve is so sensitive that the vibration of the operators arm due to the hammering action of the piston jars the thumb to such an extent that it is difiicult to hold it steadily for the minimum opening of the throttle valve. In my present device, a small amount of air can first be admitted and this same amount of opening is maintained with ease by the operator before the main valve is opened to provide for maximum speed.

It will now be apparent that I have devised a novel and useful two stage throttle valve for percussive tools, which embodies the features of advantage enumerated as desirable in the statement of the invention and the above description, and while I have, in the present instance, shown and described a typical embodiment thereof which will give in practice satisfactory and reliable results, it is to be understood that the the following instrumentalities: a bushing having ports communicating with said passage, a main valve slidable in said bushing and controlling said ports, said main valve having a passage communicating with said ports, an auxiliary valve controlling the main valve passage, a ball located above said valves, and means coacting with said ball to effect the opening first of said auxiliary valve and thereafter of said main valve, whereby the initial opening of said auxiliary valve will cause" the hammering piston to operate at a minimum speed and the opening of the main valve will cause the hammering piston to operate at a maximum speed.

2. A percussive tool handle provided with a grasping portion and having a passage for communicating with said the motive fluid, and a throttle mechanism controlling said passage and comprising a bushing having ports communicating with said passage and havin a valve seat, a main valve slidable in said ushing and controlling said valve seat, said-main valve having,

a passage through it communicating with said ports, an auxiliary valve controlling said main valve passage, a spring cooperating with one of said valves, a ball located above said valves and a lever to actuate said ball controlllng said ports, said main valve havand valves and arranged to open the auxil iary valve prior to the opening of the main valve, whereby the initial opening of said auxiliary valve will cause the hammering piston to operate at a minimum speed and the opening of the main valve will cause the hammering piston to operate at a maximum s eed. 7

3. A percussive tool handle provided with a grasping portion and having a motive fluid passage, and a throttle valve mecha nism comprising a bushing having ports passage, a main valve slidable in said bushmg and controlling said bushing ports, said main valve having a passage through it communicating with the bushing ports, an auxiliary valve controlling the main valve passage, a lever on said handle, and a ball valve actuated by said lever to effect the opening first of said auxiliary valve and thereafter of said main valve, whereby the initial depression of said lever will open said auxiliary valve and cause the hammering piston to operate at a minimum speed and a further depression of said lever will open said main valve and cause the hammering piston to operate at a maximum speed.

4. A percussive tool handle provided with a grasping portion and having a passage for the motive fluid, and a throttle mechanism comprisin the following instrumentalities: a bushingdlaving ports communicating with said passage, and having a valve seat, a main valve having a head slidable within said bushing and having a valve head controlling said valve seat, said main valve having a passage through it communicating with said ports and provided with a valve seat, an auxiliary valve controlling the main valve passage and having ,a stem passing through said main valve, a lever carried by said handle,- a ball interposed between the auxiliary valve stem and said lever and tive' fluid-passage, and throttle mechanism controlling said passage and comprising a mam 'valve controlling said passage, said main valve having a passage communicating with the ban e-passage,-'an auxiliary valve controlling the main valve passage and extending through the main valve, a ball carried by said main valve and cooperating with both Valves to effect their opening, and means to move said ball.

6. A percussive tool handle having a motive fluid passage, and throttle mechanism controlling said passage and comprising a bushing having ports communicating with said passage, a closure for one end of said bushing, a mam valve in said bushing and sure, a ball valve carried by said main valve,

and preventing leakage through said pasf sage, and means coacting with said ball valve to open the auxiliary valve prior to the opening-of the main valve.

7. A tool handle having a motive fluid passage, and throttle mechanism controlling said passage and. comprising a bushing having at one end an inlet port communicating with said passage and havinga port through its side wall communicating with'said .passage, a main valve having a groove intermediate its ends and having a valve head controlling'said end port, said main valve having a passage communicating with the bushing ports, an-auxiliary valve controlling the main passage and having a stem extending through the mainvalve, a ball contacting with the main valve to open it on a predetermined opening of the auxiliary valve,

and a lever carried by said handle and bearing against said ball.

8. A percussive tool handle having a motive fluid passage, and throttle mechanism controlling said passage and comprising a bushing having ports communicating with said passage, a main valve controlling said ports and having a passage through it communicating with said ports, an auxiliary valve controllingthe' main valve passage and having a stem extending through the end of the main valve, one end of said valves being exposed to the pressure of the motive fluid, a

flit

lit

medium of said ball valve to eflect first the.

opening of the auxiliary valve and thereafter the opening of the main valve. A

9. A percussive tool handle having a motive fluid passage, and throttle valve mechanism controlling said passage and comprising a bushlng communicating by ports with said passage, a main valve controlling said ports and having a passage through it communicating with the handle passage and having a passage extending through its end, an auxiliary valve controlling the main valve passage and having a stem extending through the passage exterior of the end of the main valve, a ball normally engaging the end of the auxiliary valve stem and preventing leakage of fluid around the valve stem when the auxiliary valve is open, and

a lever to advance said ball, whereby the auxiliary valve is opened and the ball then engages the main valve to effect its opening.

10. The combination of a pneumatic tool handle, a two-stage throttle valve mechanism therein, a manually operated lever pivotally mounted in said handle, and a ball interposed between said lever and said twostage throttle valve mechanism, the initial depression of said lever causing said valve mechanism to open to cause the hammering piston to operate at a minimum speed and a further depression of the lever causing the valve mechanism to further open to cause the hammering piston to operate at a maximum speed.

11. The combination of a pneumatic tool handle, a manually operated lever pivotally mounted therein, a closure for the lower portion of said handle, an auxiliary valve located in said handle, a spring intermediate of said auxiliary valve and closure, said valve being located intermediate of said spring and lever, and a main valve coacting with said auxiliary valve, both said main and auxiliary valves being actuated by said lever, the opening of said auxiliary valve preceding the opening of said main valve, whereby the initial depression of said lever eflects the opening of the auxiliary valve to cause the hammering piston to operate at a minimum speed and a'further depression of said lever upon the main valve causes the hammering piston to operate at a maximum speed.

12. The combination of a pneumatic tool handle, a two-stage throttle valve mechanism mounted therein, and comprising an upwardly seating auxiliary valve and an upwardly seating main valve, a spring for holding said valves normally seated, both of said valves seating in the direction of the incoming motive fluid, and the seating of said main valve when said auxiliary valve is initially unseated being eflected by said motive fluid, and a pivotally mounted manually operated lever for actuating said main and auxiliary valves, whereby the initial depression of said lever effects the opening of the auxiliary valve and causes the hammering piston to operate at a minimum speedand a further depression of said lever effects the opening of the main valve and causes the hammering piston to operate at a maximum speed.

13. The combination of a pneumatic tool handle having a pressure supply duct extending through the grasping portion I thereof, a two-stage throttle valve mechanism also mounted in the grasping portion of said handle, and comprising an upwardly seating auxiliary valve and an upwardlv seating main'valve, a spring for holding said valves normally seated, both of said valves seating in the direction of the incom ing motive fluid which passes through said pressure supply duct, the seating of said main valve when said auxiliary valve is initially open being effected by said motive fluid, and a pivotally. mounted manually operated lever for actuating said main and. auxiliary valves, whereby the initial depres sion of said lever eflects the opening of the auxiliary valve and causes the hammering piston to operate at a minimum speed and a further depression of said lever effects the opening of the main valve and causes the hammering piston to operate at a maximum speed.

14. The combination of a pneumatic tool handle having a pressure supply duct extending through the grasping portion thereof, a two-stage throttle valve mechanismalso mounted in the grasping portion of said handle and comprising an upwardly seating auxiliary valve and an upwardly seating main valve, a closure for the lower portion of said handle, a spring intermediate said closure and said valves for holding the latter normally seated,.both of said valves seating in the direction of the incoming motive fluid and the seating of said main valve when said auxiliary valve is initially unseated being effected by said motive fluid, and a pivotally mounted manually operated lever mounted in the upper portion of said handle for actuating said main and auxiliary valves, whereby the initial depression of said lever eflects the opening of the auxiliary valve and causes the hammering piston to operate at a minimum speed and a further depression of said lever eflects the opening of the main valve and causes the hammering piston to operate at a maximum speed.

15. The combination of a pneumatic tool handle, a bushing located therein, a twostage throttle valve mechanism comprising a main valve and an auxiliary valve carried by said bushing, a manually operated lever 1. iounted in a slit in said handle and connections common to said manually operated lever and said two-stage throttle valve mechanism, whereby the initial depression of said lever will open said auxiliary throttle valve and cause the hammering piston to operate at a minimum speed and a further depression of said lever will open said main throttle valve and cause the hammering piston to operate at a maximum speed.

16. The combination of a pneumatic tool handle, a bushing located in the grasping portion thereof, a two-stage throttle valve mechanism, comprising a main valve and an auxiliary valve carried by said bushing, and a manually operated lever mounted in the grasping portion of said handle, said manually operated lever being adapted to actuate both said auxiliary valve and said main valve, whereby the initial depression of said lever will open said auxiliary throttle and cause the hammering piston to operate at a minimumspeed and a further depression of said lever will open said main throttle and cause said hammering piston to operate at its maximum speed.

17. Thecombination of a pneumatic tool handle, a bushing located in the grasping portion thereof, a two-stage throttle valve mechanism, comprising a main valve and an auxiliary valve carried by said bushing,

and means carried by said handle and operable by the thumb or finger of the operator for actuating said valves, said means initially opening said auxiliary throttle, to

cause the hammering piston to operate at minimum speed, and next opening said main throttle to cause said piston to operate at maximum speed.

CHARLES H. HAESELER.

Witnesses:

FRANK E. GILEs, JOHN M. Moxnns. 

